The present invention relates to a controllable electric solenoid valve of a brake system of a motor vehicle according to the preamble of the main claim.
German Patent Application 43 05 488 A1 has already described a control circuit for a solenoid valve. With this control circuit, the trigger current for the solenoid valve is controlled so that the valve closing body is braked shortly before being moved from its flow-through position to its closed position. This yields the result that the solenoid valve closes with very little noise and thus interfering sound waves are not transmitted through the brake system to the motor vehicle. The virtually noiseless closing is achieved by briefly turning off the trigger current to support the valve closing body in the end position with a holding current.
German Patent Application 197 07 960 A1 also describes a method and a device for regulating the pressure in a wheel brake, a regulator for pressure regulation forming a trigger signal from the pressure relationships prevailing at the valve arrangement. To improve the quality of regulation for the pressure regulation in the brake circuit, one valve arrangement is provided for pressure buildup and another for pressure reduction. By measuring the actual brake pressure and comparing it with the setpoint pressure, a difference is determined and taken into account with an altered trigger signal. The relationship between the trigger signal and the pressure relationships is stored as a characteristic curve for the pressure buildup and/or pressure reduction.